Project Summary Lead can enter drinking water when service pipes that contain lead corrode, especially where the water has high acidity or low mineral content. Lead is a toxic heavy metal that can be harmful to human health even at low exposure levels, and it can bioaccumulate in the body over time. Young children, infants, and fetuses are particularly vulnerable, and even low levels of exposure have been linked to damage to the central and peripheral nervous system, learning disabilities, shorter stature, impaired hearing, and impaired formation and function of blood cells. Current methods for lead measurement in drinking water require someone to send a water sample to a laboratory, where bulky instruments are used to evaluate lead concentrations, and the results get back in a few days. While some colorimetric test strips are available on the market that can be used to measure lead in homes, they lack the accuracy needed, and the cost of each test strip is >$10, too expensive for people who want to determine lead levels in their tap water frequently. Intelligent Optical Systems, Inc. (IOS) proposes to develop a low-cost, simple, and reliable home-use test kit for measuring lead in tap water to better protect families from lead poisoning. The proposed test kit is based on a highly innovative method of combining aptamers with nanomaterials, making the kit highly selective and sensitive for lead testing. The test kit will be easy to use; simply add tap water to the test kit vial and the water will change color according to the concentration of lead in the water. Each test kit will cost<$2. With the proposed test kit, householders can check their tap water quality regularly and avoid lead poisoning.